What do clouds on Mars seem like? Effectively, a brand new video stitched collectively from pictures captured by NASA’s Curiosity rover provides a glimpse. On this video, delicate red-and-green-tinted clouds are seen drifting by way of the Martian sky in hanging patterns that look much like those Earth clouds make. Finding out how and the place on Mars these clouds type can assist scientists higher perceive their impression on the planet’s local weather.
The photographs, which had been captured on Jan. 17 by one in all two cameras onboard Curiosity, function “noctilucent” or twilight clouds — clouds captured wafting so excessive up within the Mars sky that they’re illuminated by daylight even when it’s night time on the planet’s floor. The snapshots had been collected over 16 minutes and sped up about 480 occasions to end result within the video above, based on a statement by NASA’s Jet Propulsion Laboratory, which constructed Curiosity and leads the mission.
These twilight clouds, that are manufactured from carbon dioxide ice — in any other case often called dry ice — could be seen on the prime of the brand new pictures. They had been floating about 37 to 50 miles (60 to 80 kilometers) above the floor, the place it’s cooler than on the floor and causes carbon dioxide in Mars’ ambiance to condense into clouds. A few of the ice crystals could be seen raining down on the floor as thick, white plumes earlier than disappearing about 31 miles (50 kilometers) excessive, the place they evaporate attributable to rising temperatures.
This marks the fourth Mars 12 months Curiosity has witnessed the incidence of those clouds, which generally seem throughout early fall within the planet’s southern hemisphere, based on the JPL assertion. They had been first noticed again in 1997 by NASA’s Pathfinder mission from simply north of Mars’ equator.
“I will at all times keep in mind the primary time I noticed these iridescent clouds and was certain at first it was some colour artifact,” Mark Lemmon, an atmospheric scientist on the Area Science Institute in Colorado, who led a paper summarizing Curiosity’s first two seasons of twilight cloud observations, mentioned within the assertion. “Now it is grow to be so predictable that we will plan our photographs upfront; the clouds present up at precisely the identical time of 12 months.”
Final September, scientists unveiled the most extensive map of clouds on Mars ever created, put collectively from 20 years of pictures captured by the European Area Company’s (ESA) Mars Categorical orbiter. The map cataloged a outstanding number of cloud patterns occurring on Mars, together with some not like something seen on Earth.
“Clouds on Mars are simply as various and engaging as these we see in our skies on Earth,” Daniela Tirsch, a planetary geologist on the German Aerospace Heart, who was concerned with the catalog, mentioned on the time.
But, why the twilight clouds have not been noticed elsewhere on Mars stays a puzzle for Lemmon and different scientists. For instance, the Perseverance rover has not detected any twilight clouds since touchdown in Jezero Crater in 2021, which lies within the northern hemisphere, farther north than Pathfinder’s location. Curiosity, too, didn’t see them until 2019, practically seven years after it landed within the Gale Crater simply south of Mars’ equator.
“Carbon dioxide was not anticipated to be condensing into ice right here, so one thing is cooling it to the purpose that it might occur,” Lemmon mentioned within the assertion.
It is attainable that sure areas are extra vulnerable to forming them, he says, comparable to areas the place ripples within the ambiance often called gravity waves cool the ambiance sufficient to freeze carbon dioxide molecules and sculpt the resulting clouds.
“However,” Lemmon added, “Martian gravity waves should not absolutely understood and we’re not solely certain what’s inflicting twilight clouds to type in a single place however not one other.”
